Injector



Oct. 9, 1934. P. I.. soon 1,976,040

INJECTOR Original Filed July 27, 1931 2 Sheets-Sheet 1 ar I Iiji.

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f p A w dzitowzgg Oct. 9, 1934. SCOTT 1,976,040

INJECTOR Original Filed July 27, 1951 2 Sheets-Sheet 2 2/2175; I. 500195 5} M A am Patented Got. 9, 1934 INJECTQR Philip Lane Scott, Chicago, 111., assignor to Super Diesel Tractor Corporation, La Porte, 11nd, a corporation of New York Application July 27, 1931, Serial No. 553,3'31 Renewed February 2d, 193% 9 Claims.

continuation in part of copending application.

116,282, filed June 16, 1926, now Patent 1.8l6,157, dated July 28, 1931.

An object of the invention is to provide a means for translating a steady flow of energy represented by the steady movement of a body of liquid at relatively low pressure into an intermittent delivered energy represented by the intermittent discharge of small bodies of liquid at high pressure. A particular object is to accomplish this result without the use of mechanical driving mechanism. Another object is to attain the advantages of the well known rotary pump structures in conjunction with a high pressure fuel delivery system suitable for use on a high speed internal combustion engine. Other objects will appear from time to time throughout the specification and claims.

Figure 1 is a vertical cross section of the com-. bined rotary pump power supply, motor, and high pressure pump. v

Figure 2 is an end elevation of the same structure.

Figure 3 is a detail section showing the portion of the high pressure accumulator and relief mechanism.

Referring to Figure 1, L is a housing. It has a reduced portion L and is provided with a cover L and a spacer plate L In it is embodied a well known type of gear pump comprising the gears M M mounted respectively on a driving shaft M and a stub shaft M M has a perforation M and M is provided with a perforation M These perforations extend through the spacer L and into the housing L. Formed within the cover L is a circular-groove M concentric with the gear M and provided with the outlet connection W. Formed concentrically with the gear M in the cover L is a second circular groove M which is provided with an inlet connection M Communicating with the intake space M in the gear M chamber is an inlet connection M which is joined by means of a pipe M with the connection M While the invention has In the pipe M is a surge tank M Communicating with the compression or pumping space M in the gear chamber is an outlet or high pressure connection M which is joined by means of a pipe M to the connection M N is a bore located within the housing L. N is a reduced bore communicating with the bore N and located in the reduced portion L of the housing. N is an upper passage axially aligned with the connection M N is a passage connecting the passage N to the large bore N. N is a passage in the housing L axially aligned with the connection M N is a passage joining the passage N to the bore N. N is a generally U-shaped passage lying in the spacer L communicating with the end of the bore N closest to the gears and have ing its extremities in alignment with the grooves M and M Normally the passages N N and N are cut ofi from communication with the grooves. When, however, the rotation of the gears bring their perforations into alignment with one or the other passages, they are for an interval in communication with the grooves and fluid can pass into them.

O is a bore in the housing L within which is located a ball valve 0 which may be held against excessive displacement by means of a pin 0 O is an enlarged passage communicating with the passage 0 and having within it a second ball valve 0 P is an intake conduit from a fuel or other fluid supply and it is joined by means of a fitting P and a passage P to the bore 0. P isan outlet conduit joined by means of a connection P to the bore 0 Q is the larger end of a diiierential plunger. It is mounted for reciprocation in the bore N. Q is the small end of a difierential plunger and it lies within the bore N Q is an adjusting screw which may be adjusted in or out to vary the limit of movement of the plunger in the direction of the plunger toward the gears. R is an extension formed as an integral part of the cap L containing within it a large bore R which connects with the passage M by means of the small passage R Lying within the bore R is a spring loaded piston R having a leather sealing washer R upon its face. R is a spring permitting the piston R to yield under pressure.

R is a sealing cap for the bore. R is a lateral passage connecting the bore R with a smaller parallel bore R R is an enlargement of the bore R containing within it a pressure release valve R held upon its seat by a spring R The tension of the spring R may be adjusted by the adjusting screw R". The passage is sealed against leakage by a cap R R is a lateral passage leading into the bore R. R is another passage connecting the passage R with the inlet passage M whereby oil which may escape through the pressure release valve may return to the suction side of the pump. S is a spray valve which may be inserted into the wall S of the engine cylinder. It is attached by means of the connection S to the pipe P leading from the high pressure chamber 0 of the pump.

The use and operation of my invention is as follows:

A relatively heavy oil, suitable for use in any of the common types of gear pumps, is placed in the surge tank M Upon rotation of the gears steady suction is created, for example in the passage M and a steady pressure is created in passage M within the capacity of the pump. The pressure on the driving oil in M will extend through the pipe M and into the channel M. A distributing port M is drilled in the gear M. As this gear rotates this port will come into register with the mating opening in L and consequently with the passages N and N This will permit the oil under pressure to act upon the reduced area of the motor piston Q causing it to move toward the gears, withdrawing the high pressure plunger Q with it and causing a suction stroke in the high pressure pump. This suction stroke causes the discharge valve 0* to seat and the suction valve 0 to lift in a conventional manner permitting the chamber to fill with liquid fuel. Coincident with the registration of the port M with its respective passages, the port M in the other gear registers also with the U-shaped passage N in the-spacer L This permits oil previously lying behind the motor piston Q to be discharged into the channel M from thence into the passage M and so back in the surge tank M thus completing a cycle of the driving liquid. The power stroke of the motor piston Q is caused by a reversal of the above steps, namely, the port M registers with thechanneF'N High pressure oil is then admitted from the channel M through the port and passage to the power side of the piston driving it forward and thereby driving a pump plunger Q forward causing a high pressure discharge to take place in the pump chamber, the valve 0 seating and the valve 0 lifting, the liquid, fuel oil for example, being then delivered to the fuel valve S in the engine. The driving oil which was used to cause the suction stroke of the motor piston can be expelled through the passages N N the port M in the gear which has then come into register, and finally the passage M into the surge tank M It is to be noted that the pump plunger Q is of considerably smaller diameter than the motor piston Q. Consequently any unit pressure-developed upon the driving oil will be multiplied substantially in inverse ratio to the diameters of the plunger and piston upon the fuel oil which is pumped by the plunger Q The purpose of the hydraulic accumulator and its associated pressure relief valve is, first, to absorb the steady delivery caused by the steady rotation of the gear pump as it is fed to an intermittent output circuit. It is obvious that the hydraulic motor piston only receives oil during a relatively small portion of one complete revolution of the gears. During the time that the control port is out of register with the motor passages the oil will be continued to be fed by the gears and will pass into the chamber R gradually compressing the spring loaded piston R When a high pressure port registers with the motor passage the oil so held in the accumulator R will be delivered in addition to the steady supply from the gears to provide the necessary quantity of oil under pressure. The pressure relief valve R serves not only to control the operating pressures in the circuit but also to take care of any accidental stoppages which would cause an undue pressure rise.

It will be seen that this system permits the'relatively cheap and simple structure of a gear pump operating with a liquid particularly chosen for such purpose to develop, finally, an intermittent high pressure upon light, non-viscous fuels, such as fuel oils, which will be high enough to operate satisfactorily an atomizing nozzle in a high speed engine. This transfer of energy from low pressure to high pressure and from steady to intermittent is accomplished without the use of mechanical linkages. It is a well known fact that mechanical linkages are unsuited for use in high speed high pressure injection engines.

Although in the form shown there is but one combined motor pump unit, the structure lends itself equally well to a multiplicity of such units, all operating from the same power supply, namely, a rotary oil pump. It will be understood that the invention'may take the form of such a multiple pump or other equivalent forms of the structure embodying the same principle, the showing here being largely diagrammatic.

- I claim:

1. In a hydraulic transmission system comprising a low pressure rotary pump, a motor cylinder, a closed liquid circuit including said pump and cylinder, a piston adapted to be reciprocated in the cylinder by the driving liquid from the rotary pump,.a pump cylinder, a piston therein directly connected to and of smaller diameter than the motor piston, a high pressure circuit including said pump cylinder, whereby the low pressure in the rotary pump circuit is converted into intermittent high pressure in the reciprocating pump circuit.

2. In a hydraulic transmission system comprising a low pressure rotary pump adapted to discharge driving liquid at a constant, relatively low pressure, substantially independent of the quantity of liquid discharged by it within its working range, a motor cylinder, a closed liquid circuit including said pump and cylinder, a piston adapted to be reciprocated in the cylinder by the driving liquid from the rotary pump, a pump cylinder, a piston therein directly connected to and of smaller diameter than the motor piston, a high pressure circuit including said pump cylinder, whereby the constant low pressure in the rotary pump circuit is converted into intermittent high pressure in the reciprocating pump circuit.

3. In a hydraulic transmission system comprising a low pressure rotary pump, a motor cylinder, a closed liquid circuit including said pump and cylinder adaptedto contain a relatively viscous driving liquid, a piston arranged to be reciprocated in the cylinder by the driving liquid from the rotary pump, a pump cylinder, a piston therein connected to and of smaller diameter than the motor piston, a high pressure circuit including said pump cylinder and adapted to contain an open high pressure circuit including said pump cylinder adapted to pump relatively non-viscous liquid, whereby the low pressure in the rotary pump circuit is converted into interthe rotary pump, a pump, cylinder, a piston there-' in directly connected to and of smaller diameter than the motor piston, a high pressure circuit including said pump cylinder and adapted to contain an open high pressure circuit including said pump cylinder adapted to pump relatively nonviscous liquid, whereby the low pressure in the rotary pump circuit is converted into intermittent high pressure in the reciprocating pump circuit.

5. In a hydraulic transmission system comprising a low pressure rotary pump adapted to discharge driving liquid at a constant, relatively low pressure, substantially independent of the quantity of liquid discharged by it within its working range, a motor cylinder, a closed liquid circuit including said pump and cylinder adapted to contain a relatively viscous driving liquid, a

piston arranged to be reciprocated in the cylinder by the driving liq d from the rotary pump, a pump cylinder, a piston therein connected to and of smaller diameter than the motor piston, a high pressure circuit including said pump cylinder and adapted to contain an open high pressure circuit including said pump cylinder adapted to pump relatively non-viscous liquid, whereby the constant low pressure in the rotary pump circuit is converted into intermittent high pressure in the reciprocating pump circuit.

6. In a hydraulic transmission system, a continuous delivery low pressure pump adapted to supply low pressure driving liquid at constant pressure substantially independent of the quantity of liquid discharged by it within its working range, a highpressure pump adapted to deliver liquid intermittently'at high pressure, transfer means associated with both of said pumps, said means including a double acting hydraulic motor piston and a high pressure reciprocating pump piston attached thereto, and of smaller diameter than the motorpiston, valve means for admitting and discharging driving liquid to and from said motor piston whereby said motor piston and the attached high pressure piston are caused to perform alternate power and return strokes.

1. In a hydraulic transmission system, a low pressure pump adapted to deliver a non-fluctuating, impulse free supply of low pressure driving liquid at constant pressure substantially independent of the quantity of liquid discharged by it within its working range, a high pressure pump adapted to deliver liquid intermittently at high pressure, transfer means associated with both of said pumps, said means including a double acting hydraulic motor piston and a high pressure reciprocating pump piston attached thereto, and of smaller diameter than the motor piston, valve means for admitting and discharging driving liquid to and from said motor piston whereby said motor piston and the'attached high pressure piston are caused to form alternate power and return strokes, and whereby said steady low pressure input is converted into intermittent high pressure output;

8. In combination in a compound hydraulic pump, a high pressure pump including a housing, a pump plunger and intake and discharge valves associated therewith, a hydraulic motor piston directly connected to said high pressure plunger, a housing containing said motor piston, ducts in said housing arranged to lead driving liquid to, and to discharge spent driving liquid from each side of said piston, means adapted to admit and discharge driving liquid to and from said passages, means for supplying a steady flow of relatively low pressure driving liquid, said means including a pair of rotating gears.

9. In a combination in a compound hydraulic pump, a high pressure pump including a housing, a pump plunger and intake and discharge valves associated therewith adapted to pump relatively non-viscous liquid, a hydraulic motor piston directly connected to said high'pressure plunger, a housing containing said motor piston, ducts in said housing arranged to lead relatively viscous driving liquid to, and to discharge spent driving liquid from each side of said piston, means adapted to admit and discharge driving liquid to and from said passages, means for supplying a steady flow of relatively low pressure viscous driving liquid, said means including a pair of rotating gears.

PHILIP LANE SCOTT. 

